Coating composition and method of producing



Patented May 22, 1945 UNITED STATES PATENT OFFICE COATING COMPOSITION AND METHOD OF I PRODUCING Paul H. Scrutchfi'eld, Hopewell, Va., assignor to Hercules Powder Company, Wilmington, Dell, a corporation'of Delaware No Drawing. Application June 26, 1942, Serial No. 448,679

' 20 Claims.

This invention relates to coating compositions and to a method for their production, and more particularly to improved coating compositions containing modified rosin esters and to a method for their production.

In my application for U. S. Letters Patent, Serial No. 413,479, filed October 3, 1941, now.U. S. Patent 2,331,805, and entitled "Synthetic resin and process of producing the same, I have de-' scribed the preparation of a novel and very desirable synthetic resin comprising a reaction product of an alcohol and a conjoint condensation product of a rosin or rosin ester, an aldehyde, and an alpha, beta-unsaturated polycarboxylic acid. Such a resin may be prepared, for example, by reacting suitable proportions of N wood rosin,

formalin, and maleic anhydride in benzene-so1u-.

tion to form a conjoint condensation product, which may then be esterified with glycerol to form a hard resin. These resins are possessed of a very high melting point and other desirable properties which make them'very advantageous for a variety of uses.

Now, in accordance with this invention I have discovered an improved coating composition which contains as the resin constituent a reaction product of a polyhydric' alcohol and a conjoint condensation product of the simultaneous reaction of a mixture consisting essentially of a rosin,

an aldehyde, and an alpha, beta-unsaturated polycarboxylic acid. Thus, these improved coating compositions comprise a drying or semidrying oil, a solvent, and a reaction product of a polyhydric alcohol and a conjoint condensation product of a rosin, an aldehyde, and an alpha, betaunsaturated polycarboxylic acid. If desired, these coating compositions may also contain suitable driers and pigments. .The coating compositions may be prepared in accordance with this invention by contacting a drying or semidrying oil and the aforementioned condensation product under conditions adapted to produce a composition of the desired properties, after which this composition may be diluted with a solvent to produce the finished coating composition. When the coating composition of-this invention is prepared in accordance with this method, it is found that the composition will body in a short kettling period and that the finished coating composition is characterized by a rapid drying rate and by other very advantageous properties.

Having thus indicated in a general way the nature of this invention, the following examples are oflered to illustrate the preparationot the novel I coating compositions which contain as a resin ingredient a reaction product of a polyhydric alcohol and a condensation product .01 a rosin, an aldehyde, and anfalpha, beta-unsaturated polycarboxylic acid. In the specification and in the 5 claims, the parts and percentages are by weight unless otherwise indicated.

Example 1 Eight hundred parts of polymerized rosin (polymerized in solution in benzene by means of 100% sulfuric acid and having a drop melting point of 98 C.) were dissolved in benzene to form a solution having a solids content of 60%, and 75 parts of formaldehyde (as 35.6% formalin) and 43.75

parts of maleic anhydride added. The emulsion thus formed was vigorously agitated and then refluxed for 5-7 hours at 75-85 C. After distilling oii the volatile components from the mixture, the condensate obtainedwas heated to 240 C. and held there for minutes under a pressure of 15 mm. of mercury. This condensate was then esterifled with 11 parts. of pentaerythritol per 100 parts of condensate at ass-295 c. until no further decrease inthe acid number'of the resin was obztserved. This required that the esterificatlon be conducted for a period of about 16 hours. After the esteriiication was complete, a resin having a drop melting point of 194 C., an acid number of. 14.5 and a color of E- (U. S. Standard) was 30 provided. Two hundred fifty parts of this tln-j ished resin and 500 parts of Z4 bodied linseed oil were heated to 585 F. in 1 hour and held at that temperature for 33 minutes. The mixture was then allowed to cool to 475 F. and was thinned 35 with mineral spirits having a boiling range of about 300-400 F. to a solution containing.50% solids. A varnish having a Gardner-Heidi; viscosity of H and a Hellige color of 7L was obtained.

Naphthenate driers wereadded to this varnish to give 0.2% calcium, 0.1% lead, and 0.07% cobalt, based upon the weight of the oil. This varnish set dust free in 2 hours and minutes and dried tack free to aluminum foil in 8% hours.

Example 2" checked with 3'75 parts of the same oil, thus reducing the temperature of the mixture to 320 F.

, The varnish was then reheated to 585 F. in 50 minutes and held at that temperature for 1 hour and 50 minutes. The mass was allowed to cool to 475 F. and thinned with mineral spirits to a solution containing 50% solids. The varnish had a Gardner-Holdt viscosity of 13+ and a Hellige color of 4L. Naphthenate driers were added to give 02% calcium, 0.1% lead, and 0.07% cobalt,

based upon the weight of the oil. This varnish dried "dust free in 2 hours and 45 minutes and tack free to aluminum foil" in about 8% hours.

Example 3 Two hundred fifty parts of the resin employed in Example 2 and 100 parts of X bodied linseed oil were heated to 585 F. 11145 minutes and held at that temperature for 10 minutes. Four hundred parts of Z4 bodied linseed oil were then added and the temperature of the mixture fell to about 300 F. The temperature was raised to 585 F. in 50 minutes and held at thattemp'eratureior 5 minutes. The mass was then allowed to cool to 475 Rand thinned with mineral spirits to a solution containing 50% solids. The varnish obtained had a Gardner-Holdt viscosity of 12+ and a Hellige' color of 4. The same proportions of the same driers were added as were employed in the preceding examples, to provide a composition which dried "dust free" in 2 hours and 45 minutes and tack free to aluminum foil" in hours.

Example 4 Two hundred fifty parts of the resin employed vention by cooking a drying oil or semidrying oil and a reaction product of a polyhydric alcohol and a conioint condensation product of a rosin, an aldehyde, and an alpha, beta-unsaturated polycarboxylic acid to form a varnish base, allowing the base to cool somewhat, and thereafter I adding a suitable solvent. In the examples, the

oil and resin were cooked at 585 F. Generally, any temperature between about 500 and about 620 F., and preferably between about 560 and about600 F., will be found to be suitable for 'kettl ing the oil and the resin. -In the examples,

' at 585 F is from about 15 minutes to about 1 hydride condensates are of linseed oil having a hour. The kettling procedure shown in Example 2 is employed when very high melting point glycerol esters of rosin-formaldehyde-maleic anheated with a linseed oil having a Gardner-Holdt viscosity greater than Z because it is found that the resin is incompatible with the linseed oil when the kettling procedure shown in Example '1 is used. This incompatibility may be overcome, as shown in Example 2, by precooking the resin with a small amount Gardner-Holdt viscosity between about X and about Z, and then cooking this mixture with sumcient oil of the desired viscosity to produce a varnish of the desired oil length. After the resin-oil combination has reached the desired degree of polymerizatic it at that temperature for'20 minutes, after which -100 parts of tung oil were added and stirred in well. The mass was then allowed to cool and was thinned'with mineral spirits to provide a composition containing solids. Driers were added as in the previous examples to provide a I varnish which dried dust free in 2 hours and 15- minutes and "tack free to aluminum foil in 6% hours.

Eaample 5 A condensate was prepared in the manner described in Example 1 by refluxing 2000 parts of WW gum rosin, 1333 parts of benzene, 120 parts of maleic anhydride, and 514 parts of 36.5% formalin. One-thousand six hundred seventeen 1 .parts of this condensate were esterifled with 205 parts of pentaerythritol to give a resin having 170 0., and a .Lovibond color of 40 Amber+3.1 Red. A'mixture containing 250 parts of this flnished resin and 400 parts of Z2 viscosity heatbodied dehydrated castor oil was heated in an inert atmosphere to 585 F. in minutes and held at that temperature for a period of 50 minutes. The mixture-was" then cooled and reduced to 50% solids using mineral spirits. The varnish so prepared had a Gardner-Holdt viscosity of D g and a color of 4 Hellige. Dri'ers were added to this varnish as metal naphthenates using 0.5%

lead and 0.05% cobalt based on'the oil content.

The varnish with driers when applied to glassand,

steel panels set to touch in 50 minutes, was "dust I an acid number of 15, a drop melting pointof -.,,positionscovered .by this invention.

place-of the resin prepared from an N wood rosin.

a temperature from is usually allowed to cool to and is then thinned about 400 to about 500 F. with a suitable solvent.

The resins suitable for use in the preparation of the coating compositions of this inventioncomprise the broad class of the reaction products of a polyhydric alcohol and a conjoint condensation product of a i'osin, an aldehyde, and an alpha-, beta-unsaturated polycarboxylic acid.

Such resins may be prepared from'any polyhydric alcohol. Hence, in place of the resins prepentaerythritol shown in the examples,,there may be used in a resin prepared from ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethyiene glycol, dipentaerythritol, digiycerol, polyglycerol, polypentaerythritol, sorbitol, mannitol, etc.

pared from glycol and Any rosin may be employed toprepare the re- 7 action product which is used in the coating com- Thus, in

shown in Example 2, there may be used a resin prepared from any wood. or gum rosin, or the pure rosin acids contained therein, such as abietic acid,

etc. Transformation products of any of these rosins may also be employedin the making ofresins suitable for use in the preparation of the improved coating compositions. As such, there may be utilized partially hydrogenated rosins, preparedfor example according to the method described in U. 8. Patent 2,174,651 to Rollin J. Byrkit, Jr., and polymerized rosins. In Example 1, the polymerized rosin employed was polymerized by means of. a sulfuric acid catalyst, but ,in its place there may which has been polymerized with the aid of any of the other known polymerization catalysts, such be employed a polymerized rosin as boron fluoride, aluminum chloride,- etc. Heat modified lower alcohol esters of any of the aforementioned'rosins, for example, the esters of alcohols having tour or less carbon atoms, are equivalent to any of these rosins in the preparation of the conjoint condensation product, which is esterified to produce the resin employed in the prepitirati'on of the coating compositions of this invenion.

These reaction-products may be prepared from any aldehyde in place of the formaldehyde shown in Example 1. Thus, there may be used formaldehyde in any of itsother modifications as anhydrous formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, furiural, benzaldehyde, aldols', etc. Also, any alpha, beta-unsaturated polycarboxylic' acid may be employed in preparing the reaction products which are used in the making of the improved coating compositions. Hence, in place of the maleic anhydride employed in Example 1, there may be used maleic acid, fu-

maric acid, itaconic acid, citraconic acid, .etc.,.

and acids which decompose under the reaction conditions to produce an alpha, beta-unsaturated polycarboxylic acid, such as malic acid. Methods for the preparation of the reaction product of a polyhydric alcohol and a conjoint condensation product of a rosin, an aldehyde, and an alpha, beta-unsaturated acid are described in greater detail in my application, Serial No. 413,471, referred to before in this specification.

Any of theusual drying or semidrying oils may be used in the preparation of the coating compositions. In the examples, linseed and dehydrated castor oils are shown, but in their place there --may be employed tung oil, soybean oil, perilla oil,

fish oil, rapeseed oil, hempseed oil, walnut oils, fishoil dimer, fractionated fish oil triglyceride, oiticica-oil, etc. While any of these oils may be used in the raw state, it is highly desirable that all of them except tung oil be prebodied according' to procedures well known in the art. The amount of oil which may be used may vary from contain from about to about 75% of solids, and preferably from about 35 toabout 60%.

Metal oxides and salts, such as litharge, cobalt acetate, manganese dioxide, lead acetate, etc.,

may be added to the varnish as driers during the heating of the resin and oil, according to methods well known in the art. The driers may also be added as soluble naphthenates or resinates to the varnish after it has reached room temperature. When the varnish is to be used as an air drying finish, the drier content. should amount to.from 0.0 to about 1.0% lead, 0.0 to about 1.0% calcium, from about 0.01 to about 0.1% cobalt, and from about 0.0 to 0.1% manganese, all based upon the oil content of the varnish, and a drier composition of 0.2% calcium, 0.1% lead, and 0.07%

cobalt, based upon the oil content of the varnish, gives very desirable drying properties. For baking finishes, the amount of drier may be reduced considerably and will normally be less than about 0.1% calcium, less than 0.1% lead, and about 0.005 to about 0.07% cobalt, based on the oil content of the varnish. These amounts of driers are given merely as approximations, and should in about 2 to about 100 gallons of oil per 100 pounds of resin, but preferably from about 5 to about gallons of oil per 100 pounds of resin is used.

After the varnish base has been cooked to provide a composition having the proper body, it may be permitted to cool and then thinned with a solvent. In general, the varnish base is allowed to cool to' 400-500-F. before the solvent is added, but the solvent may be added at other temperatures. In the examples, the varnish base was thinned with mineral spirits, but in its place there maybe used any of the usual varnish thinners,- such as the paraflln hydrocarbons as heptane, V.

M. 8: P. naphtha, turpentine, etc., the coal tar hydrocarbons as benzene, toluene, xylene, etc.,

decahydronaphthalene, tetrahydronaphthalene,

Solvecso No.11, 2, 3, 4, etc. In the examples, the coating composition contained 50% solids. The

amount ot'solids which the coating composition may. contain will depend upon the viscosity desired/in the dual mixture and upon other factors.

no way be construed as limiting the scope and applicability of the invention. If desired, the usual pigments may be added to the coating composition to produce an enamel.

The coating compositions prepared as described in the specification may be made in a very short kettling'period and dry in a short time to form ahard enduring film. These compositions find general use wherever clear varnish and enamels have heretofore been employed.

This application is a continuation-in-part of my application, Serial No. 413,479, filed October 3, 1941, now U. s. Patent 2,331,805, and entitled Synthetic resin and process of producing the same." I

What I claim and desire to protect by Letters Patent is: l

1. A coating composition comprising a material selected from the group consisting of drying oils and semidrying oils and a reaction product of a polyhydric alcohol and a conjoint condensation product of the simultaneous reaction of reactants consisting essentially of a. rosin compound selected from the group consisting of rosin acids.

and lower monohydric alcohol esters thereof, an aldehyde, and an alpha, beta-unsaturated polycarboxylic acid.

.2. A coating composition comprising a solvent, a material selected from the group consisting of drying oils and semidrying oils and a reaction product of a, polyhydric alcohol and a conjoint condensation product of the simultaneous reaction of reactants consisting essentially of a rosin compound selected from the group consisting of rosin acids and lower monohydric alcohol esters thereof, an aldehyde, an an alpha, beta-unsaturated polycarboxylic acid.

3. A coating composition comprising a solvent, a material selected from the group consisting .of drying oils and semidrying oils and a reaction product of a polyhydric alcohol and a conjoint condensation product of the simultaneous reaction of reactants consisting essentially of polymerized rosin, an aldehyde, and an alpha, beta '4. A coating composition comprising a solvent, a material selected from the group consisting of drying oils and semidrying oils and a reaction product of a polv ydric alcohol and a conjoint a u, mm ti composition will condensation product of the simultaneous reac- 4 tion of reactants consisting essentially of partially hydrogenated rosin, an aldehyde, and an alpha, beta-unsaturated polycarboxylic acid.

5. A coating composition comprising a solvent,

a material selected from the group consisting of drying oils and semidrying oils and a reaction product of a. polyhydric alcohol and a conjoint condensation product of the simultaneous reaction of reactants consisting essentially of isoreaction product of glycerol and a conjoint conmerized rosin, an aldehyde, and an alpha, betaunsaturated polycarboxylic acid.

6. A coating composition comprising a solvent, a material selected from the group consisting of drying oils and semidrying oils and a reaction product of glycerol and a conjoint condensation product of the simultaneous reaction of reactants consisting essentially' of polymerized rosin, an aldehyde, and an alpha, beta-unsaturated polycarboxylic acid. 7. A coating composition comprising a solvent, a material selected from the group consisting of drying oils and semidrying oils and a reaction product of glycerol and a conjoint condensation product of the simultaneous reaction of reactants consisting'essentially of partially hydrogenated irosin, an aldehyde, and an alpha, beta-unsaturated polycarboxylic acid.

8. A coating composition comprising a solvents a material selected from the group consisting of drying oils and semidrying oils and a reaction 3 product of glycerol and a conjoint condensation ,product of the'simultaneous reaction of reactants ;consisting essentially of isomerized rosin, an aldehyde,, an an alpha, beta-unsaturated polycarjboxylic acid.

; 0. A coating composition comprising a solvent, a material selected Irom the grcup consisting of drying oils and semidrying oils-and a reaction ,product of glycerol and a conjoint condensation product of the simultaneous reaction of reactants consisting essentially of polymerizedrosin, formaldehyde, and maleic anhydride.

10. A coating composition comprising a solvent,

3 a material selected from the group consisting of 5 idrying oils and semidrying oils and a reaction j product of glycerol and a conjoint condensation 1 product of the simultaneous reaction of reactants consisting essentially of partially hydrogenated j rosin, formaldehyde, and maleic anhydride.

11. A coating composition comprising a solvent, 1 a material selected from the group consisting of I drying oils and semidrying oils and a reaction 1 product of glycerol and a conjoint condensation product of the simultaneous reaction of reactants 1 consisting essentially" of isomerized rosin, formaldehyde, and maleic anhydride.

12. A coating composition comprising mineral densation product ofthe simultaneous reaction of reactants consisting essentially of isomerized I rosin, formaldehyde, and maleic anhydride.

15. A coating composition comprising mineral spirits, a drier, a material selected from the group consisting of drying oils and semidrying oils and a reaction product of glycerol and aconjoint condensation product of the simultaneous reaction of reactants consisting essentially of polymerized rosin, formaldehyde, and maleic anhydride.

' 16. A coating composition comprising mineral spirits, a drier, a material selected from the group consisting of drying oils and semidrying oils and glycerol and a conjoint cona reaction product of the simultaneous reaction of densation product of reactants consisting essentially rosin, formaldehyde, and maleic anhydride.

17. A coating composition comprising mineral spirits, a drier, a material selected from the group consisting of drying oils and semidrying oils and uct oi p l hydric 1 spirits, amaterial selected from thegroup consisting .ofdr-ying oils and semidrying oils and a 1 reaction product of glycerol and a conjoint condensation product 'ot the simultaneous reaction of reactants consisting essentially of polymerized j rosin, formaldehyde, and maleic anhydride.

1 13. A coatingrcomposition comprising mineral 1 spirltaa material selected from the-group con- 5 sisting of oils and semidrying oils and a reactants consisting essentially of 0 a reaction product of 7 glycerol and a conjoint condensation product of tion of reactants consisting essentially of isomerized rosin, iormaldehyde, and maleic anhydride.

18 The method of producing a coating comof hydrogenated the simultaneous reacposition which comprises heating together a material selected from the group consisting of drying oils and semidrying oils and a reaction prodalcohol and a conjoint condensation product ofa the simultaneous reaction of reactants consisting essentially of a rosin com pound selected from the group consisting of rosin acids and lower monohydric alcohol'esters there of, an aldehyde, and an polycarboxylic acid at a temperature between about 500 F. and about 620 F.

alpha, beta-unsaturated 19. The method of producing a coating composition which comprises heating together a material slected from the group consisting ofdrying oils and semidrying oils and a reaction product of a polyhydric alcohol and a conjoint condensation product or the simultaneous reaction of reactants consisting essentially of polymerized rosin, beta-unsaturated an aldehyde, and an alpha, polycarboxylic acidat a temperature between about 500 F. and about 620 F.

20. The method of producingca coating composition which comprises heating together a material selected from the group consisting of drying oils and semidrying oils and a reaction product of a p lyhydric alcohol and a conjoint condensation product oi the simultaneous reaction of partially hydrogenated rosin, an aldehyde, and an alpha, beta-unsaturated polycarboxylic acid at a temperature between about some. and about-620 r.

PAUL a. scau'rcmng 

